Package com.tnsai.state

Interface Checkpointer

All Known Implementing Classes:

FileCheckpointer, InMemoryCheckpointer

public interface Checkpointer

Checkpointer interface - LangGraph-style state checkpointing.

Enables:

• Session memory between interactions
• Human-in-the-loop workflows
• Fault tolerance and recovery
• Time-travel debugging

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static final record	Checkpointer.CheckpointTuple	Checkpoint tuple container.
static final record	Checkpointer.Write	Write operation.

Method Summary

Modifier and Type	Method	Description
void	delete(String threadId)	Delete checkpoints for a thread.
Checkpointer.CheckpointTuple	getTuple(String threadId, String checkpointId)	Fetch a checkpoint.
List<Checkpointer.CheckpointTuple>	list(String threadId)	List checkpoints for a thread.
void	put(String threadId, String checkpointId, Map<String,Object> state, Map<String,Object> metadata)	Store a checkpoint.
void	putWrites(String checkpointId, List<Checkpointer.Write> writes)	Store intermediate writes.

Method Details

put

void put(String threadId,
 String checkpointId,
 Map<String,Object> state,
 Map<String,Object> metadata)

Store a checkpoint.

Parameters:

threadId - Thread identifier

checkpointId - Checkpoint identifier

state - State data

metadata - Checkpoint metadata

putWrites

void putWrites(String checkpointId,
 List<Checkpointer.Write> writes)

Store intermediate writes.

Parameters:

checkpointId - Checkpoint identifier

writes - List of writes

getTuple

Checkpointer.CheckpointTuple getTuple(String threadId,
 String checkpointId)

Fetch a checkpoint.

Parameters:

threadId - Thread identifier

checkpointId - Checkpoint identifier (null for latest)

Returns:

Checkpoint tuple

list

List<Checkpointer.CheckpointTuple> list(String threadId)

List checkpoints for a thread.

Parameters:

threadId - Thread identifier

Returns:

List of checkpoints

delete

void delete(String threadId)

Delete checkpoints for a thread.

Parameters:

threadId - Thread identifier